The Problem

$ cat test-require.ts
const fs = require('fs')
fs.statSync('/')
console.log('OK')

$ ts-node test-require.ts 

TSError: ⨯ Unable to compile TypeScript
require.ts (1,12): Cannot find name 'require'. (2304)

You got the Cannot find name 'require'. (2304) Error.

However, the same code with a .js extension run by node without any problem:

$ cp test-require.ts test-require.js

$ node test-require.js
OK

I believe this problem is the most stupid design for TypeScript because it heavy increased the studying curve and lied on their slogan "TypeScript is the superset of JavaScript": a good JavaScript code will fail under TypeScript.

The Solution

1. We need to use import instead of const/var with require

- const fs = require('fs')
+ import fs = require('fs')

However, after this modification, we re-run ts-node test-require.ts will get a new TS2351 Error:

Cannot find module 'fs'. (2307)

2. In order to fix this new problem, we have to make another extra step:

$ npm install @types/node

After installed @types/node, re-run ts-node require.ts will be ok:

$ ts-node require.ts
OK

A TypeScript issue discussion at here